112 lines
2.8 KiB
Go
112 lines
2.8 KiB
Go
package cache
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import (
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"crypto/sha1"
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"fmt"
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"io/ioutil"
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"os"
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"path/filepath"
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"strings"
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"github.com/djherbis/fscache"
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"github.com/karrick/godirwalk"
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"gopkg.in/djherbis/atime.v1"
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"gopkg.in/djherbis/stream.v1"
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)
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type spreadFS struct {
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root string
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mode os.FileMode
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init func() error
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}
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const keyFileExtension = ".key"
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// NewSpreadFS returns a FileSystem rooted at directory dir. It
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// Dir is created with perms if it doesn't exist.
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func NewSpreadFS(dir string, mode os.FileMode) (fscache.FileSystem, error) {
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fs := &spreadFS{root: dir, mode: mode, init: func() error {
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return os.MkdirAll(dir, mode)
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}}
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return fs, fs.init()
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}
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func (fs *spreadFS) Reload(f func(key string, name string)) error {
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return godirwalk.Walk(fs.root, &godirwalk.Options{
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Callback: func(absoluteFilePath string, de *godirwalk.Dirent) error {
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path, err := filepath.Rel(fs.root, absoluteFilePath)
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if err != nil {
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return nil
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}
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// Skip if name is not in the format XX/XX/XXXXXXXXXXXX.key
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parts := strings.Split(path, string(os.PathSeparator))
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if len(parts) != 3 || len(parts[0]) != 2 || len(parts[1]) != 2 ||
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filepath.Ext(path) != keyFileExtension {
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return nil
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}
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keyFileName := absoluteFilePath
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dataFileName := absoluteFilePath[0 : len(absoluteFilePath)-len(keyFileExtension)]
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// Load the key from the key file. Remove and skip on error
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key, err := ioutil.ReadFile(keyFileName)
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if err != nil {
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_ = fs.Remove(dataFileName)
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return nil
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}
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// If the data file is not readable, remove and skip
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file, err := os.Open(dataFileName)
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defer func() { _ = file.Close() }()
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if err != nil {
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_ = fs.Remove(dataFileName)
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return nil
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}
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f(string(key), dataFileName)
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return nil
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},
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Unsorted: true,
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})
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}
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func (fs *spreadFS) Create(name string) (stream.File, error) {
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key := fmt.Sprintf("%x", sha1.Sum([]byte(name)))
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path := fmt.Sprintf("%s%c%s", key[0:2], os.PathSeparator, key[2:4])
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err := os.MkdirAll(filepath.Join(fs.root, path), fs.mode)
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if err != nil {
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return nil, err
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}
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absolutePath := filepath.Join(fs.root, path, key)
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err = ioutil.WriteFile(absolutePath+keyFileExtension, []byte(name), 0600)
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if err != nil {
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return nil, err
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}
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return os.OpenFile(absolutePath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
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}
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func (fs *spreadFS) Open(name string) (stream.File, error) {
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return os.Open(name)
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}
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func (fs *spreadFS) Remove(name string) error {
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_ = os.Remove(name + keyFileExtension)
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return os.Remove(name)
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}
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func (fs *spreadFS) Stat(name string) (fscache.FileInfo, error) {
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stat, err := os.Stat(name)
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if err != nil {
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return fscache.FileInfo{}, err
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}
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return fscache.FileInfo{FileInfo: stat, Atime: atime.Get(stat)}, nil
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}
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func (fs *spreadFS) RemoveAll() error {
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if err := os.RemoveAll(fs.root); err != nil {
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return err
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}
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return fs.init()
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}
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